Interference microscopy provides an interesting biophysical approach to measuring the spatial distribution of material inside cells and other transparent objects. It has been previously shown that an adaptation of this technique, Live Cell Interferometry (LCI), can sensitively detect and track the nanomechanical properties of hundreds of cells simultaneously (1). LCI can also be used to monitor the dynamic flow of the cytoplasm inside single cells as small indentions are made by highly magnetic probes on the surface of a cell (2). Studies showed that an almost instantaneous redistribution of cell material resulted from indentation of the cell surface, which was beyond the detection limit of conventional optical microscopy.
How individual cells regulate their size is poorly understood, as is the relationship between cell mass and well characterized biochemical pathways. While quantitative mass measurements of single live cells began in the 1950s, (3, 4) only recently have newer approaches to increase the speed, precision, and practicality of cellular mass measurements become available. There is a need for new ways to rapidly and simultaneously, measure the masses of one or more cells either alone or clustered within large populations of cells (7, 8). Embodiments of the invention disclosed herein meet this as well as other needs.